Designer's Corner

Packless Valve

A recent Design News article about packless rotary valves prompted a reminder about this bent-bellows, rotary-valve seal design. In it, a bellows encapsulates the stem to prevent leakage. With one end fixed to the valve bonnet, the other end of the bellows rotates around the stem axis as the valve is opened or closed. An external housing over the stem and bellows protects and preloads the assembly to allow controlled rotation and acts as a secondary seal. Quarter-turn, half-turn, and fully rotating models are available.

Slick sensor

A flexible magnetic material enclosed within a thin stainless steel jacket lets the Speed Sense™ system monitor shaft rotation and direction without the toothed wheels normally used in Hall-effect sensing. Originally developed to reduce turbulence in hydraulic pumps, the system should also reduce losses in transmissions and compressors. The patented ring is available separately for custom applications.

Allen Anderson, Temper Corp., Fonda, NY 12068, (518) 853-3467.

Tough fenders

Plastic components on heavy equipment may come as a surprise, but Case Corp. says the polyurethane reaction-injection molded (RIM) fenders on its L-Series™ backhoes outperform steel in the application. The 24-lb, 61x21x28-inch fenders can support a 50-lb corner load and rebound from impacts in temperatures from 180°F to -20°F.

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